Blower attachment for sewing machines



'7 Sheets-Sheet 1 G. SAUER ETAL BLOWER ATTACHMENT FOR SEWING MACHINES rm-""--f- Aug. 15, 1950 G. sAUER 4EI'Al. l

BLOWER ATTACHMENT FOR SEWING'MACHINES '7 Sheets-Sheet 2 Filed DSG. 29, 1945 TTR/YE Aug 15 1950 G. sAUl-:R ET AL v2,518,725

' BLOWER ATTACHMENT FOR SEWING MACHINES Filed Dec. 29, 1945 '7 Sheets-Sheet 3 IN V EN TORS my B K 7# infamy? AUS- 15 1950 G.sAux1-:R ETAL 2,518,725

l BLOWER ATTACHMENT EOE sEwTNG MACHINES Filed nec. 29, 1945 .7 sheets-sheet 4 INVENTORS` BY C Aug. l5, 1950 G. sAuER ET AL BLOWER ATTACHMENT Foa SEWING MACHINES 7 Sheets-Sheet 5 Filed Dec. 29, 1945 aime m Elf I l lels/ENTOES. M11

BY c 7% Train/5 SNE.

Aug. 15,1950 l BLOWER ATTACHMENT FOR SEWING MACHINES Filed bec. 29, 1945 7 sheets-sheet s G. sAuER ETAL I 2,518,725

Aug. l5, 1950 G. sAuER ErAL BLOWER ATTAClmENT FOR SEWING MACHINES Filed Dec. 29, 1945. l

7 Sheets-Sheet '7 lull' Ill` INVENTORS.

JW BY GM C fqR/E 4 5 a M MM :V 0 M 1 ---Ml i W W 7 m Jl |W1||| f uw, //0 9 HV z z Ww oo M i I E 7 oo. w 7 m Q BLOWER ATTACHMENT "FORlS-EWNG `MACHINES George Sauer', Berwyn, and Clarence l0., Smith,

Chicago, Ill., assignors to 'Union Special Ma- 'chine Company, lChicago, Ill.,` a corporationof Illinois Application December29, 1945 Serial-lwlo.f638,186

lThisinvention relates to an improved .com-

bination of an electric transmitter, or individual power drive, and rblower for use in connection with sewing machines. It .has particular relation to a unit of this character intended-fior the improved operation o'f lindustrial sewing machines, as in the/manner disclosed inthe 4'pending application o'f Harold J. LeVesconte and Albert M. Schweda, Serial 'No. 534,718, iilecl AMay 9, 1944, now xPatent No. 2,424,102.

An 'object ofthe inventionhas been to provide a unit of the character indicated which has .the various parts requiring adjustment readily accessible -for such adjustment as well as removal and replacement. This applies `particularly to the clutch operating means, brake means, and the blower.

Another object has 'been `to provide an arrangement of and mountingmeans for thel .blower which will enable relative adjustments' between the vhousing and rotor to be quickly andeasilyaccomplished .and rwhich will also permit angular adjustment ofthe housing to Aany extent desired in relationto "the, rframe of the `transmitter or other `support member. This allows .compensa-,l

tion to be readily made forangular adjustment of the `transmitter inftightening the beltrwhich connects the latter with thefsewing machine.

.A Vfurther object: has been-to provideja mounting for the Vblower which willeliminate the neces-` .i

sity -of relative movement between, the` housing and rotor Vmembers and thus permita minimum, clearance vbetween these members,l with resulting greater efciency inthe operation vofthe blower. l

As a specn'icfeature of theinvjention, ,simple and eiective kmeans isprovided -for .preventing rotationrelative gto the frame of :an axially slidable sleeve which carries thezsh-iftable -memberzof the :clutch :means fof the transmitterA unit.

`,Other objects, features,` Yand advantages-.ofthe invention will appear from a. detailedrdescription which will now .be .given of V:sev-eral illustrative embodiments of the invention, v.in lconjunction with the accompanying.drawingsinlwhich:

-Fig.1lis 1a -front elevational view -1of=the improved unit, :including Ya Linotor,-fclutc'h, `and blower;

Fig-l2 is a view-partly lin=f-ront-elevation Vand partly -in longitudinal section/through the'unit shoWn'in-Eigjl; Y 1- Fig. l3 is =an `end#elevational viewfof :the "unit the pulley and blower removed;

i14 Claims. (Cl. 11230-42418) Figli is a view similarto Fig.3 but with the blower and pulley included;

Eig. 5is adetail .view of .a spider used in attaching the "blower housing;

'FigL6'is aview vsimilar to Fig. 2` but illustratinga `modiiiedconstruction;

Fig `7 is a view .similarfto Fig. 2 but'illustrating. a vfur-ther modication Fig. 8 is a vertical .sectional View taken along the line 8-8 of Fig. 7,; and

.'Fig. 9 yis a fragmentary 'detail view showing the form. and arrangement .of the .clutch operating lever in "the'liig, "'7 construction.

Turning now 'to Figs. l .to '5, there is illustrated one suitable `form of Ythe combined motor, clutch, Aand blower combination intended fforuse in driving afsewing machine ofan-ysuitabletype. The 'improved Vconstruction may be used in the manner illustrated in the application of Charles F. Rubel, Serial'No. 433,740, .led March 7, 1942, now Patent No. 2,423,996, or in the application of "George Sauer, Serial No. 442,585, filed May 12, 1942, now Patent No. 2,418,429.

The improved unit has a main supporting frame designated generally lby the referencey character l0. This frame, in the embodiment oi' Figs. 1 to 5, vis preferably of V-coniiguration in e'nd view '(Fig.'3`) the Vfbeing formed by a pair of yoke rmembers'A Il vand l2. Yoke member |'2 isprovided with a'rearvvardly extending 'ear I3, or 4 aV pair of Asimilar ears, adapted for pivotal mounting by means of a pin, or pins, I'4 upon the lower end of a downwardly extending arm or pair of .arms |15 'integral with, lor otherwise connected with, a supporting ,plate I6. The latter, it will be understood, isfadapted forl attachment in any convenient manner, as by means of screws or the like, to the Vunder surface of the table top which supports the sewing machine'to be driven by the unit. At -its forward end the supporting plate carries a .pair of downwardly extending ears VI7 lbetween 'which therev isswivelly mounted the upper end of a rod I8. This rod at itsupper end'is provided with a hubllike portion which fits snugly between the earsl 'il and which receives a, pivot pin rI extending through vthe ears Il., Rod i8 is screw-threaded at its lower end and carries a 'pair of kclamping 'nuts 20 adapted to embraceoppositesides :of a stud 2| extending laterally 'from a lug22 projectingoutwardly from the'meniber H Stud 2l is journ'alled inthe Vlug 2'2 Yand :is ipreferably'provided with at sides for engagement by thenuts 20. By appropriatelyA adjustingtlienuts 20along the rod 18 the frame I" may beaneularly -adjusted to a `desired posi-` 2,513,725 e *Y l tion in relation to the supporting plate I6. This, it will be understood, enables proper tightening or loosening of the belt which connects the power unit with the sewing machine.

Toward their left ends (Figs. 1 and 2) the yoke members and I2 are connected with an end bell member 23 of an electric motor 24. The opposite end of the motor may be enclosed by another bell member 25 of suitable form and the entire motor casing may suitably be held together by tie rods or bolts 26. The motor may be of any suitable construction and is provided with a driving shaft 21 which extends outwardly beyond the bell 23 a suitable distance and is journalled in a bearing 28, preferably a ball-bearing, mounted within an opening in the end bell. The outer projecting end of the shaft 21 carries a ilyWheel 29 which is keyed to the shaft and is held firmly thereon, preferably by means of a nut 38 carried by a screw-threaded reduced portion at the end of the shaft. A washer 3| is preferably employed between the Vnut 30 and the end of the hub of the flywheel.

At their other or right-hand ends, Fig. 1, the yoke members and |2 carry, preferably as an integral part thereof, the upper half portion 32 of a bearing retaining housing. The lower half 33 of this bearing housing'may be secured to the upper half by means ofscrews or bolts 34, Fig. 3. Within the bearing housing there is mounted an axially slidable sleeve 35 which carries a pair of ball-bearing units 36 and 31 in enlarged openings at itsopposite ends, these bearing units being arranged to support a driven shaft 38 which is axially aligned with the motor shaft 21. At its inner end the shaft 38 carries a driven clutch member 39 arranged to cooperate with a friction band 48 secured in any suitable way to the outer face of the flywheel 29. Clutch member 39 which is preferably formed with a frustro-conical outer surface arranged to cooperate with a corresponding inner surface on the friction bank 40, is secured to the shaft 38 by means of a tapered pin 4|. At its outer end the shaft 38 carries a pulley wheel 42. which has splined connection with the outer end of the shaft and which is held on the latter by means of a pair of nuts 43 cooperating with a screw threaded reduced portion at the end of the shaft. The arrangement is such that the clutch member 39 at one end of the shaft`38 and the pulley 42 atthe other end serves to retain the various intermediate parts, described in association with sleeve 35, as a unitary assembly. A spacing sleeve 44, surrounding the shaft 38, is provided between the bearing units 36 and 31.' Rotation of the sleeve 35 within the supporting housing is prevented by a key 45 mounted within an elongated recess 46 formed'by complementary key slots in the top of the sleeve and in the interior of the portion 32 of the bearing support. This key is secured by a screw 41 within the key seat in the sleeve 35. As will be seen, the arrangement is suchthat the sleeve 35 may be shifted axially to a limited extent with respect to the bearing support but it may not be rotated relative to such support.

The bottom portion of the sleeve 35 is formed with a plurality of rack teeth 48 which may extend for any suitable distance around the sleeve and which are adapted to cooperate with pinion teeth 49 provided in spaced relation around a rotatable stud 58. The latter is journalled within a cylindrical housing portion of the member 33 and is disposed transversely of the mainY axis of the bearing support. At its right end (Fig. 3)

is adapted to be connected, by means of a rod or chain, (not shown) with a foot treadle or other -control member conveniently positioned for operation by the operator. A spring 51 connected at one end with an intermediate point on the lever 55 and at its opposite end with an eyelet 58 carried by the frame member I serves to rock the arm 55 in a clockwise direction (Fig. 1). This, as seen in Fig. 2, tends to shift the sleeve 35 toward the right to disengage the clutch member 39 from the friction band 40. At the same time it carries a portion of the outer face 59 of the driven clutch memberv against a segmental friction member 60 which constitutes a brake. This brake segment, which preferablyhas the configuration indicated in Fig. 3, is carried by a channel in the inner` end 6| of a brake supporting slide 62.` The latter is slidably mounted in a longitudinal channel 63 (Fig. 3) formed in an upward extension of the upper member 32 of the bearing housing. The slide 62 is provided with a slightly elongated slot 64 adapted to receive a clamping screw 65 which has screwthreaded engagement with the bearing housing and which serves to Ylock the slide in any set position on the bearing housing.` For the purpose of accurate adjustment of the brake element, both initially and to compensate for wear, an adjusting screw 66 is provided. This has its shank in screw-threaded engagement with an opening'61 in the end of the slide62 and at an intermediate point it carries a flange or collar 68 which is received by a groove 69 in the top of the upwardly projecting portion of the bearing housingY 32. As will b'e seen, vrotation of the 4 screw 66 will thus produce longitudinal movement of vthe slide 62 to any extent desired. Of course the clamping screw 65 will be loosened prior to any such adjustment and will be tightened after the adjustment has been made. Y It-will be noted, incidentally, that the cooperation of the clutch member v39 with the brake element 69 provides a limit for the rocking of the lever arm 55 by the spring 51. When the lever arm is-depressed by operation of a foot treadle or the like, the stud 5|) will be rotated in a counterclockwise direction and will shift the sleeve 35 toward the left (Fig. 2) thus carrying the clutch lmember 39 into engagement with the friction band 40 on the constantly rotating flywheel 29. At such timesthe sewing machine will be driven.

We come now to the blower is adapted to provide an appropriate stream of cooling air for cooling theneedles or other oper.

ating devices of the sewing machine in accordance with the disclosuresof. the above mentioned Rubel and Sauer applications. This blower comprises a rotor having a hub portion 10 mounted on the splined portion of the shaft 38 between the innerv end of the hub of pulley 42 and the outer face of the bearing 31. Animpeller disc 1| is secured to the hub 10 by means of screws 12. Asrshown in Figs. 2 and 4, a plurality of fan orirnpeller bladesv 13, preferably of angular formation, are secured in any suitable way, as by .Welding or the like, to the Aface of'the'disc 1|.

attachment which i 5, i lfSiinroundingthemotorithere s'providedlaihousling M ;of convolute form, as.` best :shown 1in Eig. J4. This :housing is Vpreferably Iformed .in '.ftwo parts, 15 .and .16, .whichare .identical iin fform .except 'for the z fact vthat one'iis irighthand and the.. other is leithand. 'These .parts are .secured together :by .la series..of.screws.lf1.1.. .The housing :is .held .in iixed relationftothe :frame l-il :of the funit .by :means-of aspiderim'ember l"l' (.Figsgaand) which has a hub ,portion '.19 adapted .to .be Jmounted upon `a cylindrical .extension Alill .of .the .upper :and lower bearing ihousing members '-32 and .33 surrounding the sleeve 35. .A set .screw-:8| ser-vesto :hold Athe hub .o'f the spider inv v any desiredpos'itionlin-relation tothe `extension 180.. rThis-permits slight Kaxiail. adjustment .and .infinite angular ..adius`tment.. ArmsQ-Ziof-the spiderare provided withiholes 83 at their-louter :ends adapted -to receive screws 84 xfor retaining ithe housing on the spider.V Insorder that .the housing 4may-be made rever-sible and placed .either yinthe position indicated 'fin- Figs. 2 and 4, or inthe reverse vposition in which the outlet -85 .is -at the left rather than -at the lright as inFi'g v`4, -bothlsecti'onsdof thel housing arefprovided wlith threadedopening-sto receive the screws 84. Thoseopeni-ngs which are Jnot serving this function -are yclosed pff by means .of screws 86. It will Ibe understood i'that `the 'outlet l85 'of -the blower is adapted to be connectediby a flexible tube, or Yeven La'rigidtube, if desired, with any appropriate por-tion of -the sewing imachinefor eiecting the-desired-cooling action. `By virtue-oi the ffine angular adjustment foi the 'housing made possible by its mountingand its vretention inany desired position by the set lscrew Si, vaccurate compensation may Lbe made -for angular sad-justment of the fra-me 40 about the pivotal support I4, lfor belt `tightening purposes `as yhas been eX- pla-ined. T-hus, regardless Yof -the angular -p'osition of the trame fI-B, ltheou-tlet -85- may -be properlyalignedwith a tube carried' by the supporting table, for example. S0, also, the mounting ofthe housing provides a simple-adjustment :to allow for wear .of the clutch faces. AS1-these -faces wearandrthe shaft-38, together with :the rotorfoi the blower, Ais shifted further toward fthe left 'in theengagement-of theclutch, the housing Ymay'be moved slightly -in fthe same Adirection `to avoid interference-between the-rotor and the housing.

'Tur-ning -now'to -Fig. f6, a modifiedconstruction is shown lin which the housing of the :blower partakes -of the axial Ymovements -of the rotor.v Except for the mounting of fthe-'blower housing andthe construction-of the-blower itself, thereons'tructi'on illustratedoin fFig. 46 is 'identical with-that illustrated in Figs. Ito 5. Hub 7t9a of fthe spider- 'ISa which-supports thefblowerihousing, is mounted..directly.uponfthe 'outer endo'fv afshiftable sleeve 35a which :corresponds with -the `sleeve 35 of 2. The r`bear-ing housing members 32a.. and aterminate to the :left of the 'hub nillu.. .In other respectsthe.construction .is thesameas in Figs. to .5.. However, since in the Fig. Y6'ar-rangement the housing, as well vas the rotor, -will be shifted axially withv Athe sleeve 35a and the shaft 38a, a smaller .clearance .may :be provided between-the rotor andthe walls ofthe blowerhousing. Amoreeic'ient blower is thus produced. The-'same Yadvantage as explained rin--connection'with'the v'first embodiment are `provided 1in the .way :of angular andaxialad ustmentof the `housingf'in relation to its support.

In Figs.v 7., 8, .and S9, a .further modification is-l shown.- .In this :construction themain .supporting trame .for the unit .is .provided .withaa cylindrical .portion i8?! :which substantially V.elfl'osesii'the. clutch fof Athe unit. However, to providefadequate circulation .of fair .around the clutch parts and thus prevent .'overheating, -the 'cylindrical .portion ofztheframe is .preferably provided with a series of openings 88 of suitable size. Frame 'member 8:1isprovided with a pair ofearsiilg adaptedt'o .be pivotallyconnected, `by meansof axpin or bo1t290, with 'downwardly extendingmembers .9i Iof `a support 92:1arranged to be securedto .the undersurface @of :the .table which carries the :sewing machine. forwardly extending ear 93, provided onlthe :cylindrical portion 81 of the ihousin'g, carriesa clamping bolt tadapted' tofcooperate withanfelongated slot`95 in a link Qt .pivotally carried at 81 by the support member 92. Thisarrangement. provides avery simple, but effective, means for varying the angular position vof the frame for @belt tightening purposes :and the like. v`As shown in ithe drawings, .an advantage of this modiiied construction is its'simplicity and cheap'- ness fromra manufacturing standpoint. VThe parts may :be largely produced as stampings.

.A di'ierent vstyle of motor is preferably employed iin this modified construction. As 'shown in Fig. 7, what is generally known as a pump type motor 98 is employed. This has at its `righthand end -an :enlarged head 99 provided with a hat surface fiile against which acorresponding nat face at-the left end of theV portion v8'! of the frame'maybe held. series of screws lil-'I may loe-provided for attaching the frame member 81 tothe vend face of the motor. The main `motor shaft fl'llZ projects beyond the end face |00 of the motor housing into the interior of the vframe portion 3l where .it carries a flywheel H33. This ywheel is keyed to the shaft, as shown, and 'is held against axial movement by lone or morefse't screws 5F04. vOn its inner side the flywheel is provided with a series -of vanes TG5 adapted to induce vcirculation lof air, a portion of which is blown into the motor housing Aand discharged through'openings IE6 in the wall of the latter. Theiywheel w3, as inthe previous embodiments,

., constitutes the `"driving member of the clutch, and

for this'purposeis provided with a Yfrustro-oonical face l 8.1 adapted to cooperate with a corresponding'internal vvface on a friction band I8 carried within a drum-like extension of a driven clutch member img. The latter is secured by means of a tapered vpin Hf@ to a driven shaft Hl which is journalled -in ball-bearing units H2 `and H13. These units are 'mounted in enlarged recesses at V'the VolODositeends of a shi'ftable sleeve H4, which -i's..slida`bl=y received within a bearing hub l l5, formed as an integral part of an end 'closure plate Il vfor the clutch housing 87. This closure plate is secured 'by screws fi li to the end of the clutch housing. vIt will 'be seen, therefore, that the lentire drivenV part of the clutch, together with all of the associated devices may be mounted as a unitary assembly on the plate .E I6 and attached or removed from the frame whenever desired.

The means for shifting the sleeve lid to effect engagement and Vdisengagement of the clutch is partici arod or rock shaft I2l (Fig. 8)." 'This rock shaft is journalled within'bushin'gs |22 and |23 carried by a transversely extending bearing sleeve |26 formed integral with the bearing hub ||5. The bushings |22 and |23 have an outside diameter slightly greater than the external diameter of the pinion |20 and they, in turn, t snugly within the bore of the sleeve |24. A set screw |25 having its inner end cooperating with a groove in the rock shaft |2| serves to retain the latter against axial movement within the bushings |22 and |23. At its outer end the shaft |2| has secured thereto the hub of a lever arm |26. This is secured to the shaft by means of a set screw |21. A spring |28 coiled about the shaft |2| and having one end bent over the end of the bearing sleeve |22 and its other end bent over the arm |25, serves to urge the latter in a clockwise direction (Fig. 9) and thus serves to urge the sleeve i I4 toward the right (Fig. '7) to disengage the clutch. The extent of movement of the arm, sleeve, and clutch is determined by the position of a brake element |29, similar to brake element 60 and mounted in substantially the same manner in a slide |30 which may be adjusted by a micrometer screw |3| and retained in any set position by a screw |32. The end plate ||5 of the clutch housing is provided with an opening |33, of arcuate form as shown in Fig. 8, to permit the free passage therethrough of the brake and its support in the assembly and adjustment of the parts. It will be understood that the arm |26 is adapted for connection, by a rod or chain, with a foot treadle or other control member so that the clutch may be engaged against the action of the spring |28 at the will of the operator.

At the outer end of the shaft there is mounted a pulley wheel |34 in the same manner as the pulley wheel 42 in Fig. 2` Between this pulley wheel and the end of the bearing hub ||5 there is mounted a blower including a rotor |35 and a housing |35. These may suitably be of the same construction as the corresponding parts illustrated in Fig. 2. The housing may, as shown, be mounted upon a cylindrical portion of the hub ||5 by means of a spider |3l. However, if desired, the arrangement may be similar to that shown in Fig. 6 so that the spider is mounted upon the sleeve ilti rather than an extension of the hub H5.

While several illustrative embodiments of the invention have been disclosed in considerable detail, it will be understood that numerous variations may be made in the construction and arrangement oi the several parts without departing from the general principles and scope of the invention.

We claim:

l. A sewing machine power unit which comprises a support, a motor carried by said support and provided with a drive shaft, a clutch having a driving member secured to said drive shaft, said clutch having a driven member including an axially slidable shaft carried by said support, power transmitting means secured to said slidable shaft, a blower having a rotor secured to said axially slidable shaft and a housing surrounding said rotor, and readily accessible screw means for retaining said housing on said support, said screw means being arranged upon simple loosening and retightening to enable angular adjustment and resetting of said housing to any desired angular position about said slidable shaft.

2. A sewing machine power unit which comprises a support, a motor carried by said support and provided with a drive shaft, a clutch having a drivingmember secured to said. drive shaft, said clutch having a driven member including an axially slidable shaft carried by said support, power transmitting means secured to said slidable shaft, a blower having a rotor secured to said axially slidable shaft and a housing surrounding said rotor, and readily accessible screw means for retaining said housing on said support, said screw means being arranged upon simple loosening and retightening to enable angular adjustment and resetting of said housing to any desired angular position about said slidable shaft, said screw means being adapted to enable axial adjustment of said housing in relation to said rotor.

3. A sewing machine power unit which comprises a support, a motor carried by said support and provided with a drive shaft, a clutch having a driving member secured to said drive shaft, said clutch having a driven member including an axially slidable shaft carried by said support, a blower having a rotor secured to said axially slidable shaft and a housing surrounding said rotor, and means for retaining said housing on said support in any desired angular position about said slidable shait, said retaining means including a sleeve concentric with said slidable shaft and carried by said support and a hub connected with said housing adapted for angular adjustment on said sleeve.

4. A sewing machine power unit which comprises a support, a motor carried by said support and provided with a drive shaft, a clutch having a driving member secured to said drive shaft, said clutch having a driven member including an axially slidable shaft carried by said support, a blower having a rotor secured to said axially slidable shaft and a housing surrounding said rotor, and means ior retaining said housing on said support in any desired angular position about said slidable shaft, said retaining means including a member shii'table with said slidable shaft and means connecting said member with said housing for joint movement thereof.

5. A sewing machine power unit which comprises a support, a motor carried by said support and provided with a drive shaft, a clutch having a driving member secured to said drive shaft, said clutch having a driven member including an axially slidable shaft carried by Said support, a blower having a rotor secured to said axially slidable shaft and a housing surrounding said rotor, and means for retaining said housing on said support in any desired angular position about said slidable shaft, said retaining means including a sleeve surrounding said slidable shai't and shiftable therewith and a hub connected with said housing mounted on said sleeve.

6. A sewing machine power unit which comprises a support, a motor carried by said support and provided with a drive shaft, a clutch having a driving member secured to said drive shaft, said clutch having a driven member including an axially slidable shaft carried oy said support, a blower having a rotor secured to said axially slidable shaft and a housing surrounding said rotor, and means for retaining said housing on said support comprising a sleeve carried by said support and a hub mounted on said sleeve and connected with said housing.

'7. A sewing machine power unit which comprises a support, a motor carried by said support and provided with a drive shaft, a clutch having a driving member secured to said drive shaft, said clutch having a driven member including an axially slidable shaft carried by said support, a

blower having a rotor secured to said axially slidable shaft and a housing surrounding said rotor, and means for retaining said housing on said support comprising a sleeve carried by said support, a hub mounted on said sleeve and connected with said housing, and means for securing said hub to said sleeve in desired angular and axial relation.

8. A sewing machine power unit which comprises a support, a motor carried by said support and provided with a drive shaft, a clutch having a driving member secured to said drive shaft, said clutch having a driven member including an axially slidable shaft carried by said support, a blower having a rotor secured to said axially slidable shaft and a housing surrounding said rotor, and means for retaining said housing on Y said support comprising a member rigidly connected with said housing and shiftable axially with said slidable shaft but held against rotation therewith.

9. A sewing machine power unit which comprises a member adapted for attachment to a table, a motor and clutch unit having a frame pivotally connected with said member and adjustable in relation thereto for belt tightening purposes, said unit including an axially shiftable driven shaft, a blower having a rotor secured to said shaft and a housing surrounding said rotor,

said housing having a discharge outlet at one side thereof, and means for mounting said housing on said frame, said means comprising a single screw member enabling infinite angular adjustment of said housing to compensate for belttightening adjustment of said frame.

10. A sewing machine power unit which comprises a member adapted for attachment to a table, a motor and clutch unit having a frame pivotally connected with said member and adjustable in relation thereto for belt tightening purposes, said unit including an axially shiftable driven shaft having a belt pulley at its outer end, a blower having a rotor secured to said shaft adjacent the inner side of said pulley and a housing surroundin-g said rotor, said housing having a discharge outlet at one side thereof, and means for mounting said housing on said frame, said means enabling angular adjustment of said housing to compensate for belt-tightening adjustment of said frame and axial adjustment of said housing relative to said pulley.

11. A sewing machine power unit which comprises a member adapted for attachment to a table, a motor and clutch unit having a frame pivotally connected with said member and adjustable in relation thereto for belt tightening purposes, said unit including an axially shiftable driven shaft, a blower having a rotor Vsecured to said shaft and a housing surrounding said rotor, said housing having a discharge outlet at one side thereof, and means for mounting said housing on said frame, said means including a spider connected with said housing and having a hub mounted upon a cylindrical surface formed on a member carried by said frame and including screwI means cooperating with said cylindrical surface and enabling angular adjustment of said spider thereon.

12. A sewing .machine power unit which comprises a support, a motor carried by said support and provided with a drive shaft, a clutch having a driving member secured to said drive shaft, said clutch having a driven member including an axially slidable shaft, a shiftable sleeve carrying said slidable shaft and shiftable therewith on a portion of said support to engage and disengage the clutch, means for preventing rotation of said sleeve, and a blower having a rotor mounted on said slidable shaft and a housing mounted on said sleeve.

13. A sewing machine power unit which comprises a support, a motor carried by said support and provided with a drive shaft, a clutch having a driving member secured to said drive shaft, said clutch having a driven member including an axially slidable shaft, a shiftable sleeve carrying said slidable shaft and shiftable therewith on a portion of said support to engage and disengage the clutch, means for preventing rotation of said sleeve, and a blower having a rotor mounted on said slidable shaft and a housing mounted on said sleeve, a portion of said support being readily detachable from the remainder thereof and enabling removal of said sleeve, slidable shaft and blower as a unit. f

14. A sewing machine power unit which comprises a support, a motor carried by said support and provided with a drive shaft, a clutch having a driving member secured to said drive shaft, said clutch having a driven member including an axially slidable shaft carried by said support, a blower having a rotor secured to said axially slidable shaft and a housing surrounding said rotor, means for retaining said housing on said support in any desired angular position about said slidable shaft, said retaining means including a sleeve concentric with said slidable shaft and carried by said support anda hub connected with said housing adapted for angular adjustment on said sleeve, a brake member positioned between said driven member of the clutch and said housin-g for engagement by said driven member as the latter is disengaged from said driving member, and means for adjusting said brake in a direction parallel with said slidable shaft.

GEORGE SAUER. CLARENCE C. SMITH.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 656,023 Kenney Aug. 14, 1900 2,269,788 Schenk Jan. 13, 1942 2,270,650 Crocella et al. Jan. 20, 1942 2,274,457 Peets etal. Feb. 24, 1942 2,309,894 Gold et al. Feb. 2, 1943 2,390,220 Vesconte et al Dec. 4, 1945 2,418,429 Sauer Apr. 11, 1947 2,423,996 Rubel July 15, 1947 2,424,102 LeVesconte et al. July 15, 1947 

